Level probe for a shaft furnace
First Claim
1. A level probe for a shaft furnace, said furnace including a wall defining an internal volume within the furnace, said surface being chargeable with material charge and said charge defining within the internal volume of the furnace and an upper charging surface with a descending level between two successive charges of the shaft furnace, said level probe measuring and monitoring the descending level of the charging surface, comprising:
- probe foot means for determining said level;
vertical sleeve means for allowing passage of said probe means through said furnace wall;
drum means for raising and lowering the probe foot means, said drum means including;
a sealed chamber communicating the interior volume through said sleeve means,a winding drum rotatably mounted within said sealed chamber,cable means secured to said winding drum for suspending said probe foot in the interior volume, andservomotor means for activating the winding drum, said servomotor means being operable at variable speed and variable torque;
position detector means for detecting winding and unwinding of the winding drum; and
control means, responsive to said position detector means, said control means including;
a first control loop for controlling the speed of the servomotor during the lowering and raising of the probe foot means to, respectively from, said charging surface according to a predetermined relationship between measured probe position and desired speed, said relationship being specific for the downward and the upward movement of the probe foot,a second control loop for controlling the torque of said servomotor during surface level monitoring according to a predetermined relationship between probe position and desired torque,detection means for detecting moment when the probe foot means touches the charging surface,means for automatically passing the control of the servomotor from said first control loop controlling the downward movement of the probe towards the surface to said second control loop when said detection means detects the impact of said probe foot means on said charging surface,means for automatically passing the control of he servomotor from said second control loop to said first control loop at a preset probe position, said first control loop then controlling the upward movement of the probe from the surface towards said vertical sleeve means, according to the predetermined relationship between probe position and desired speed for the upward movement.
0 Assignments
0 Petitions
Accused Products
Abstract
A probe includes a probe foot which is suspended on a cable or a chain attached to a winding drum mounted in a sealed casing above the furnace and which communicates with the interior of the latter via a vertical sleeve passing through the upper wall of the furnace, an electric motor associated with a reducer for actuating the winding drum, and a device for detecting the unwinding and winding up of the winding drum in order to control the speed and torque of the motor. The motor is a servomotor, the speed and torque of which are controlled automatically as a function of the detection device by comparison of the actual speed of the motor with data of desired values dependent on the position of the probe foot.
18 Citations
8 Claims
-
1. A level probe for a shaft furnace, said furnace including a wall defining an internal volume within the furnace, said surface being chargeable with material charge and said charge defining within the internal volume of the furnace and an upper charging surface with a descending level between two successive charges of the shaft furnace, said level probe measuring and monitoring the descending level of the charging surface, comprising:
-
probe foot means for determining said level; vertical sleeve means for allowing passage of said probe means through said furnace wall; drum means for raising and lowering the probe foot means, said drum means including; a sealed chamber communicating the interior volume through said sleeve means, a winding drum rotatably mounted within said sealed chamber, cable means secured to said winding drum for suspending said probe foot in the interior volume, and servomotor means for activating the winding drum, said servomotor means being operable at variable speed and variable torque; position detector means for detecting winding and unwinding of the winding drum; and control means, responsive to said position detector means, said control means including; a first control loop for controlling the speed of the servomotor during the lowering and raising of the probe foot means to, respectively from, said charging surface according to a predetermined relationship between measured probe position and desired speed, said relationship being specific for the downward and the upward movement of the probe foot, a second control loop for controlling the torque of said servomotor during surface level monitoring according to a predetermined relationship between probe position and desired torque, detection means for detecting moment when the probe foot means touches the charging surface, means for automatically passing the control of the servomotor from said first control loop controlling the downward movement of the probe towards the surface to said second control loop when said detection means detects the impact of said probe foot means on said charging surface, means for automatically passing the control of he servomotor from said second control loop to said first control loop at a preset probe position, said first control loop then controlling the upward movement of the probe from the surface towards said vertical sleeve means, according to the predetermined relationship between probe position and desired speed for the upward movement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
Specification